Elevator-brake.



No. se|,7s4.' Pa tented Nov. I3, I900. o. F. BURTON.

ELEVATOR BRAKE.

(Application filed July 28, 1899.]

2 Sheets-Sinai I.

(No Model.)

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No. 66!,754. Patented Npv. l3, I900.

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ELEVATOR BRAKE. (Application filgd J'\ 1 1y 28, 1899.) (No Model.) 2 Sheets$hoet 2.

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UNITED STATES PATENT OFFICE.

OSCAR F. BURTON, OF BELLEVILLE, NEW JERSEY.

ELEVATOR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 661,754, dated November 13, 1900.

Application filed July 28,1899. Serial No. 725,351- (No model.)-

T0 at whom it may concern.-

Beit known that I, OSCAR F. BURTON, acitizen of the United States,residin g at Belleville, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Elevator-Brakes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to letters of referepce marked thereon, which form a part of this specification.

My invention relates to accident-brakes for elevators. By this term accident-brake as compared with an ordinary brake as used to diminish the speed of any moving body I mean a brake which will stop the moving bodyin this instance, an elevator-car-immediately. The principle underlying my improved brake is gravitation-that is, at the moment when the hoisting-cable breaks the car will be in a state of equilibrium caused by a counterbalancing-weight being attached, which forms with the actual and direct means the brake-block and the brake-lever, a part of my improved brake means, as will be more fully understood as the description proceeds.

In describing my improved brake I shall call attention to the accompanying drawings, Where like letters of reference indicate corresponding parts in both views.

Figure 1 is a side view of an elevator, the guides being broken partly away,showing the hoisting cable in operation, my improved brake means attached in the position they will be in ready to stop the car in case the hoisting-eable should snap. Fig. 2 is an elevation from the same point of view as Fig. 1, the hoisting-cable, however, being broken, thus illustrating my improved brake in operation, holding the car suspended immediately after the snapping of the hoisting-cable.

In the drawings, A indicates the elevatorcar, and B the hoisting-cable, attached to the car and passing over the sheave O, secured on the top of the framework'E, said cable having the usual counterweights attached. (Not shown or described, as they form no part of my invention.)

D is a standing cable secured fittingly at the top of framework E and at the bottom to the ring F. In order to avoid the sudden sharp strain on the standingoable D attendant upon the action of my improved brake means on said cable, a spring S, of some resilient material,is secured between the framework E and'the disk H, forming part of the means of attachment for the standing cable D at the top, and a turnbuckle I is attached at the lower end of the cable to give the said cable the proper tension. Passing over a sheave J, attached on the top of framework E, is a cable K, to one end of which a counterweight Lis attached, the other end being secured fittingly to my improved brake-lever M. The brake-lever M is bolted, by means of the bolt M, to one end of the link N, the other end of the brakelever being bolted to my improved brake-block P by means of a bolt P. The link N is pivotally attached at its other end to a bearing-block 0, said block secured on the top of the elevator-car A.

The brake-lever M is constructed as follows: The arm M is furnished with a head M having aswelling, said swelling movin g eccentrically with regard to the pivot P and having its edge when the brake means are called into action pressed against the standing cable D, so as to cause a bend in the said cable, as seen in Fig. 2. The other arm M of the brake-lever M is located between two bushes B and B firmly secured to the hoisting-cable B, and is to that efiect forked, a prong of such fork lying on either side of the cable, the object of said bushes being to keep the lever M in an appropriate horizontal position. The brake block P is furnished with the sheaves Q to Q and is, as before stated, pivotally attached to the brake-lever M by means of the bolt P in the head M Of the sheaves Q to Q it will be seen that Q and Q and Q and Q respectively, lie in pairs on either side of the standing cable D, acting thus in the capacity of guiding-sheaves and, further, preventing any friction on said cable. Sheaves Q and Q placed, as they are, adjacent to and with the head M touching the standing cable opposite to and between them,will, in connection with the said swelling, jam the part B of the standing cable thus lying between them, as will be more fully understood when the operation of my improved brake means are described in cooperative unison.

serving Fig. 2, the cooperation of the brake It can now be understood from the description of the above elements that as long as the hoisting-cable B is in operative order and carries the elevator-car A up and'down the counterweight L and the car A simply move correspondingly without the weight of either coming into play, the brake elements then beingin rest, as seen in Fig. 1. When obelements with each other is as follows: The link N, attached to the car A bymeans of the bearing-block O,has at its other end the brake lever M pivotally attached to it, said lever further having the cable K secured to it, which cable K, passing over the sheave J, has at its other end the counterweight L attached. As the brake-block P is pivotally connected to the brake-lever M, it will be readily seen that it moves conjointly with said lever, the sheaves Q to Q guiding it up and .down the standing cable. Taking now the positionillustrated in Fig. 2, showing the hoisting-cable snapped, it will be seen that the weight of the carAwill when unsupported by the hoisting-cable B force the arm M of the brake-lever downward by reason of the connection existing between the lever M and the car A by means of the metallic link N. This downward movement of the arm M re sults in a turning of the lower curve of the swelling on the head M so as to force the (standing) part B of the standing cable lying between said swelling and the sheaves Q and Q over against such sheaves and jammingit tightly there, the car further being counterbalanced and held in equilibrium by the counterweight L now having come into full play with the separation from the hoistings cable. The main features productive of this resultwill consequently be seen to be a brakelever turnished With-a head having a swelling caused to move eccentrioally around a certainvpivot when the hoisting-cable breaks and connected with a counterbalancing cable and weight, said brake lever pivoted to a brake-block guided along the standing cable.

I might state here that the brake-lever, the brake block, and the link connecting the brake-lever with the elevator-car are made of metal, as constituting the only material durable and strong enough to fulfil the functions demanded of said-elements. In these above-mentioncdmeans the main features of my invention are thus embodied, and

have hereunto set my hand this 27th day of July, A. D. 1899.

OSCAR F. BURTON. Witnesses: I

PERoY 'L. GALLAGHER, AUGUST M. TRESOHOVV. 

